FedEx Cup winner Horschel will make his first appearance since winning the $10million bonus for topping the PGA Tour's points list in the 2014 season in September.
Horschel clinched the cash bonus with back-to-back wins at the BMW Championship and the Tour Championship in September, preceded by a runner-up finish at the Deutsche Bank Championship - all three being Cup play-off events.
Japan's Matsuyama had a steady FedEx Cup play-off campaign, making it through to the 30-man Tour Championship where he finished 22nd behind Horschel.
The 22-year-old - winner on tour at the Memorial Tournament in June - began his 2015 campaign in strong fashion, finishing tied for third at the Frys.com Open in Napa.
The season-opening Frys.com Open - won by South Korea's Bae Sang-moon, also in the field this week - saw Australia's Jarrod Lyle make a momentous return to the US tour.
Lyle - competing on a medical extension - made his second career comeback from leukemia, qualifying for the tournament on Monday before tying for 31st in a brilliant performance.
"To come here without a tournament to play, and then get through on the Monday and make the cut and play reasonable golf for four days, I couldn't ask for anything better," Lyle said.
"It's something to build on for the rest of the year."
Lyle will also compete at TPC Summerlin in Las Vegas, his second and final event of 2014 - as he chases a total of $283,825 in 20 events this season to reclaim his tour card proper.
Other notables in contention at the $6million event include Scotland's Martin Laird - who has finished in the top 15 at his past three starts - and defending champion Webb Simpson.
Simpson enjoyed a strong 2014 season after his win in Las Vegas, earning top-10 finishes in nine of his 25 starts.
Most recently, the 2012 US Open winner competed in the USA's losing Ryder Cup team at Gleneagles.